Bad sector on disk failing mdadm RAID array and marking all disks as spares.

[Greg]

Binary package hint: mdadm

Description: Ubuntu 10.04.1 LTS
Release: 10.04
64bit
mdadm - v2.6.7.1 - 15th October 2008

I have a failing hard drive that is in a 3 disk RAID 5 software array. I am using mdadm to create/manage the array. When a sector goes bad on the disk it freezes Ubuntu. Upon restart the array becomes degraded and says that there is not enough devices to start the array. If I boot to a live CD and install mdadm and check the status of the array. It has all 3 drives marked as spare drives.

The following is how I correct the problem. While still login to the live CD I run a badblocks scan (badblocks -nsv) on the failing drive. At this point I believe that the drive sees the bad block and marks it as such. I then shutdown and remove the failing drive's SATA cable. Then I boot back into the live CD install mdadm and force assemble the array. I then shut back down and reconnect the failing drive's SATA cable. The array boots degraded then I re-add the failing drive back into the array to get rebuilt.

What i expected to happen is that Ubuntu marks the sector or drive as failed and does not freeze. If it just marks it as failed then i can run a badblocks scan on the drive and the drive can remap the bad sector. At which point I can re-add the drive back to the array all while Ubuntu is still up and running

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.